Amazon Stonehenge or Calçoene megalithic observatory is megalithic structure located in Amapa state, Brazil. It consists of 127 blocks of granite, each up to 4 metres tall, standing upright in circles at the bank of river on a hilltop. During the excavations there have been found numerous ceramic fragments and whole urns with charred bones, soil and red pigment. Based on ceramic fragments found nearby, archaeologists believe this structure is between 500 and 2000 years old.